Canada – Re-evaluation Decision RVD2024-04, Predacide Uses of Strychnine and Sodium Monofluoroacetate and their Associated End-use Products
Health Canada’s Pest Management Regulatory Agency
7 March 2024
ISSN: 1925-1025 (PDF version)
Catalogue number: H113-28/2024-4E-PDF (PDF version)
Overview
Health Canada has recently completed the re-evaluation of the predacide uses of strychnine and sodium monofluoroacetate. These are both restricted pesticides that are used to protect wildlife, livestock, and people by killing predators (wolves, coyotes and black bears) or skunks. These pesticides are only registered for use in Alberta, and can only be used by authorized people. Health Canada assessed these pesticides together based on the similarity of their use patterns and toxicity profiles. After considering all the information available for the evaluation, Health Canada has decided to:
cancel all uses of strychnine and
continue registration of sodium monofluoroacetate uses with additional risk reduction measures in place.
For strychnine: Based on new information received during the public consultation, Health Canada updated its environmental risk assessment of the use of strychnine. As a result, Health Canada found that strychnine uses did not meet the requirements for protection of the environment and is cancelling all uses.
For sodium monofluoroacetate: Information received during the public consultation did not change the assessments for sodium monofluoroacetate. As described in the proposed re-evaluation decision (PRVD2022-18), Health Canada found that sodium monofluoroacetate uses are effective and continue to meet the requirements for protection of human health and the environment. Health Canada will continue registration of sodium monofluoroacetate uses provided that additional risk-reduction measures are put in place, including updated product labels and a product stewardship program that includes education, training, and increased monitoring of product use.
This final re-evaluation decision applies to all registered products containing strychnine and sodium monofluoroacetate.
This page includes details from selected parts of the final re-evaluation decision (RVD) document focussed on key aspects of the decision. The purpose of this summary is to help improve the understanding of Health Canada’s pesticide decisions.
The technical details of the re-evaluation are available in the final Re-evaluation Decision document. If you would like to read the document, please visit the Request Publication page for RVD2024-04: Re-evaluation Decision for predacide uses of strychnine and sodium monofluoroacetate and their associated end-use products .
On this page
Strychnine and its uses
Sodium monofluoroacetate and its uses
Strychnine: re-evaluation process
Sodium monofluoroacetate: re-evaluation process
Required product label changes for sodium monofluoroacetate
Product stewardship program
Predacide use in other countries compared to Canada
Comments outside the scope of the re-evaluation decision
Next steps
How to find out more
Related information
The term “predacide” refers to a pesticide used to kill vertebrate predators. Predators can pose threats to livestock, vulnerable wildlife (such as woodland caribou) and people.
This re-evaluation decision focuses on the use of strychnine or sodium monofluoroacetate on coyotes, wolves, and black bears, as well as skunks that may spread rabies.
Predacide use in Canada is restricted. Currently, it is only allowed to be used in Alberta to kill problematic wildlife as a last resort when all other management options have failed.
Strychnine and its uses
Strychnine is a restricted animal toxicant (poison) registered for use as a predacide in Alberta. Only authorized Government of Alberta or municipal employees can store, handle or use strychnine products.
Strychnine is used as a last resort to kill:
wolves, coyotes, and black bears through poisoned meat baits
skunks through poisoned egg baits
This predacide is used to protect livestock, vulnerable wildlife and people from predators or to kill skunks in rabies control programs.
Sodium monofluoroacetate and its uses
Sodium monofluoroacetate (also known as Compound 1080) is a restricted animal toxicant (poison) only registered for use as a predacide in Alberta. Only authorized Government of Alberta employees can store, handle or use sodium monofluoroacetate products.
Sodium monofluoroacetate is used as a last resort to kill:
wolves and coyotes through poisoned meat baits
This predacide is used to protect livestock vulnerable wildlife or people from predators.
Strychnine: Re-evaluation process
Final decision for strychnine
Under the authority of the Pest Control Products Act , Health Canada is cancelling all predacide uses of strychnine.
Basis of the final decision for strychnine
Health Canada scientists conducted assessments to determine the potential impact of continuing the registration of strychnine in Alberta. This included assessments of information related to product use records, exposure to humans, benefits (value), and impact on the environment for strychnine.
Based on the information available when the scientists conducted these assessments, Health Canada proposed to continue registration of strychnine uses, provided that additional risk-reduction measures would be put in place, such as updating product labels and a product stewardship program. The goal of this program was to make sure people used and handled these restricted products properly. This would be achieved through training and educating users, and monitoring use records. Health Canada published this proposed re-evaluation decision (PRVD2022-18) and held a public consultation.
During the 90-day public consultation for the proposed decision, Health Canada received comments and new information that led to updates to the environmental assessment of strychnine uses. As a result, Health Canada found that strychnine did not meet the requirements for protection of the environment and is cancelling all uses.
All strychnine products are cancelled and will be phased out within six months from the publication date of this final decision.
Key evidence supporting the decision to cancel strychnine
Environment
Since Health Canada received new information during the public consultation period, the environmental risk assessment was revised. The new information included use records for strychnine that were not available for consideration in the proposed re-evaluation decision for strychnine (PRVD2022-18).
Based on this use record information, Health Canada found that there was more strychnine used than the number of poisoned carcasses retrieved. This means that there were strychnine-poisoned carcasses available in the environment for other animals to feed on which increases the risk of secondary poisoning.
Considering this new information, Health Canada scientists concluded that the continued registration of predacide uses of strychnine does not meet the requirements for protection of the environment. Since practical risk-reduction measures to protect non-target animals cannot be identified and to minimize the impact on biodiversity, Health Canada is cancelling all uses of strychnine with a six-month phase-out period.
For the six-month phase-out period of strychnine, Health Canada scientists concluded that the current limited use pattern and approved product label conditions for strychnine meet the requirements for the protection of the environment.
A reference list of relevant information used to make this final decision is included in the proposed re-evaluation decision document (PRVD2022-18) and the re-evaluation decision document.
Other information considered for the decision to cancel strychnine
Human health
For the six-month phase-out period of strychnine, Health Canada scientists concluded that the current use pattern and approved product label conditions for strychnine meet the requirements for the protection of human health.
Incident reports
No new human, domestic animal or environmental incidents involving strychnine were reported to Health Canada for the re-evaluation.
Value
Health Canada expects that the cancellation of strychnine uses will have a low impact on predator and skunk management because there are other methods to manage these animals. These methods are explained below.
For wolf, coyote and black bear management, these methods may include:
educating the public about these threats,
putting up fencing,
having guardian animals,
improving wildlife habitat for vulnerable wildlife,
trapping,
shooting, and
using sodium monofluoroacetate poisoned baits as a last resort.
For skunk management, these methods may include:
vaccinating,
trapping, and
shooting.
Furthermore, people in Alberta have not used strychnine for skunk management since the 1990s. This is because there have not been any outbreaks of skunk rabies since then.
Learn more about:
Pesticide assessments in Canada
Pesticide compliance and enforcement
Proposed Re-evaluation Decision PRVD2022-18, Predacide Uses of Strychnine and Sodium Monofluoroacetate and their Associated End-use Products – Canada.ca
Request Publication page for RVD2024-04: Re-evaluation Decision for predacide uses of strychnine and sodium monofluoroacetate and their associated end-use products
Framework for risk assessment and risk management of pest control products: PMRA guidance document
Label search – Health Canada
Sodium monofluoroacetate: Re-evaluation process
Final decision for sodium monofluoroacetate
Under the authority of the Pest Control Products Act , Health Canada is continuing registration of the predacide uses of sodium monofluoroacetate provided that additional risk-reduction measures are put in place, including updated product labels and a product stewardship program.
Basis of the final decision for sodium monofluoroacetate
Health Canada scientists conducted assessments to determine the potential impact of continuing the registration of sodium monofluoroacetate. This included assessments of information related to product use records, exposure to humans, value, and impact on the environment for sodium monofluoroacetate.
Based on the information available when the scientists conducted these assessments, Health Canada proposed to continue registration of sodium monofluoroacetate uses, provided that additional risk-reduction measures would be put in place, including updated product labels and a product stewardship program. The goal of this program was to make sure people use and handle these restricted products properly. This would be achieved through training and educating users, and monitoring use records. Health Canada published this proposed re-evaluation decision (PRVD2022-18) and held a public consultation.
During the 90-day public consultation for the proposed decision, information submitted to Health Canada during the public consultation did not change the assessments related to human health, environmental or value for sodium monofluoroacetate. As a result, Health Canada’s decision to continue registration of sodium monofluoroacetate uses does not change.
The additional risk-reduction measures required as conditions for continued registration of sodium monofluoroacetate must be implemented within 24 months from the publication date of this final decision. This includes product label updates and a product stewardship program.
Key evidence to support the decision to continue registration of sodium monofluoroacetate
Information submitted to Health Canada during the public consultation did not change the assessments related to human health, environment or value for sodium monofluoroacetate, so this final re-evaluation decision is unchanged from the proposed re-evaluation decision (PRVD2022-18). Additional risk-reduction measures are still required as a condition of continued registration, including product label updates and a product stewardship program.
Human Health
The human health assessment that supports the re-evaluation decision for sodium monofluoroacetate (PRVD2022-18) focuses on whether the existing product label and use directions protect:
people who use the pesticide, and
people located near where the pesticide is used (bystanders).
Based on the human health assessment, Health Canada scientists concluded that:
people using sodium monofluoroacetate are protected when using personal protective equipment (PPE)
bystanders are protected because of disposal requirements for poisoned baits and animal carcasses.
Health Canada scientists also considered comments received during the consultation period about how the proposed requirement to dispose of poisoned baits or carcasses by incineration at approved provincial treatment facilities is not practical. Based on this information, the scientists concluded that the existing bait and carcass disposal directions on product labels are appropriate for reducing potential exposure to bystanders and preventing accidental killings of non-target animals. As a result, the proposed requirement for disposal of poisoned baits and carcasses by incineration was removed. To continue to protect people, disposal of any unused sodium monofluoroacetate product and empty product containers will still be at an approved provincial treatment facility.
Additionally, the product registrant must set up a product stewardship program. As part of this program, there must be an educational component focused on proper disposal of these products and their associated contaminated wastes. For example, a new requirement is for users to record the disposal of poisoned baits and carcasses in a “Vertebrate Toxicant Usage Record”.
Considering the previous assessment and the required updates for product labels, Health Canada scientists concluded that the predacide uses of sodium monofluoroacetate meet the requirements for protection of human health.
Environment
The environmental assessment that supports the re-evaluation decision for sodium monofluoroacetate (PRVD2022-18) is based on an analysis of toxicity to animals and usage records available at the time.
Based on the environmental assessment, Health Canada scientists concluded that:
sodium monofluoroacetate is toxic to birds and mammals, but it is more toxic to animals in the canine family (canids) than other animals, and
the risk of accidental killings of non-target animals by secondary poisoning from sodium monofluoroacetate is much lower than for strychnine because scavenging animals would need to eat many times their body weight in sodium monofluoroacetate-poisoned tissues to reach toxic levels.
In addition, Health Canada scientists noted that fewer than 3000 tablets of sodium monofluoroacetate are used annually in Alberta which shows that the product is not used heavily.
Health Canada scientists also considered comments received during the consultation period about the potential risk to aquatic organisms. Even though sodium monofluoroacetate is not allowed to be used in water, the scientists conducted a screening level risk assessment for aquatic organisms using available information for sodium monofluoroacetate. The screening level risk assessment assumed that the maximum amount of sodium monofluoroacetate allowed to be used at a site was dropped into a small wetland. The assessment showed that potential risks to aquatic organisms from this pesticide accidentally contaminating water bodies are extremely low.
To further protect non-target animals, the product registrant must set up a product stewardship program. As part of this program, there must be an educational component focused on proper handling and use of these products and management of poisoned baits and carcasses. For example, a new requirement is for users to complete a “Vertebrate Toxicant Usage Record” and submit the information to the registrant.
Considering the environmental risk assessment and the required updates for product labels, Health Canada scientists concluded that the predacide uses of sodium monofluoroacetate meet the requirements for protection of the environment.
A reference list of relevant information used to make this final decision is included in the proposed re-evaluation decision document (PRVD2022-18) and in the re-evaluation decision document.
Other information considered for the decision to continue registration of sodium monofluoroacetate
Incident reports
No new human, domestic animal or environmental incidents involving sodium monofluoroacetate were reported to Health Canada for the re-evaluation.
Value
The value assessment that supported the proposed re-evaluation decision for sodium monofluoroacetate (PRVD2022-18) was based on an analysis of the pesticide’s performance and its benefits at the time.
With strychnine being cancelled, using sodium monofluoroacetate poisoned baits is another method for managing wolves and coyotes. This method can be used as a last resort when all other methods have failed.
These other methods for managing wolves and coyotes may include:
educating the public about these threats,
putting up fencing,
having guardian animals,
improving wildlife habitat for vulnerable wildlife,
trapping, and
shooting.
Learn more about:
Pesticide assessments in Canada
Pesticide compliance and enforcement
Proposed Re-evaluation Decision PRVD2022-18, Predacide Uses of Strychnine and Sodium Monofluoroacetate and their Associated End-use Products – Canada.ca
Request Publication page for RVD2024-04: Re-evaluation Decision for predacide uses of strychnine and sodium monofluoroacetate and their associated end-use products
Framework for risk assessment and risk management of pest control products: PMRA guidance document
Label search – Health Canada
Required product label changes for sodium monofluoroacetate
To make product labels clearer, Health Canada requires the following general updates:
Improving use directions
Adding statements about using other strategies before sodium monofluoroacetate can be used
To protect human health and the environment, Health Canada requires the following risk-reduction measures:
Human health
To protect people, Health Canada requires the following product label changes as a condition of continued registration of the predacide uses of sodium monofluoroacetate:
Updating personal protective equipment (PPE) requirements to meet current product labelling standards and specifying that the PPE must be worn when handling the product, poisoned baits and carcasses.
Clarifying disposal statements for poisoned baits and carcasses, including requiring users of this pesticide to record these disposals in the “Vertebrate Toxicant Usage Record.”
Environment
To protect the environment, Health Canada requires the following product label changes as a condition of continued registration of the predacide uses of sodium monofluoroacetate:
Clarifying reporting requirements, including requiring users of this pesticide to complete a “Vertebrate Toxicant Usage Record.”
Prohibiting the use of small baits and large baits at the same time for a target animal.
Clarifying instructions on the limited ways this product can be used on coyotes and wolves.
Prohibiting the use of vegetation to cover baits.
Product stewardship program
To further protect human health and the environment when using sodium monofluoroacetate, the product registrant must set up and maintain a product stewardship program. The goal of this program is to make sure people use and handle this restricted-class pesticide properly.
As a minimum requirement, the product registrant must:
Develop and implement a training program on how to properly use sodium monofluoroacetate and dispose of poisoned baits and carcasses. This includes making sure people know that they can only use the product after all other predator management methods have failed.
Keep, monitor and maintain records related to using sodium monofluoroacetate, through the “Vertebrate Toxicant Usage Record.”
Submit reports of accidental killings of non-target animals and any other relevant incidents following the Incident Reporting Regulations.
Notify Health Canada within 24 hours when any use record indicates that the product label directions were not followed. Stop the use of sodium monofluoroacetate until Health Canada reviews and provides direction.
Predacide use in other countries compared to Canada
Strychnine
Strychnine is currently registered for use in other Organisation for Economic Co-operation and Development (OECD) member countries, including the United States and Australia.
In the United States, strychnine is registered as a rodenticide for underground use to control pocket gophers.
Sodium monofluoroacetate
Sodium monofluoroacetate is currently registered for use in other Organisation for Economic Co-operation and Development (OECD) member countries, including the United States, Australia and New Zealand.
In the United States, sodium monofluoroacetate is only registered for use in a livestock collar.
Comments outside the scope of the re-evaluation decision
During the 90-day public consultation for the proposed decision on the predacide uses of strychnine and sodium monofluoroacetate, the majority of comments Health Canada received were part of a letter-writing campaign expressing concerns for animal welfare and that these pesticides should be banned.
In 2018, Health Canada conducted a public consultation on the consideration of humaneness during the approval of pesticides for the control of vertebrate predators. In 2021, Health Canada published a summary of this public consultation and determined that humaneness would not be incorporated into the pesticide risk assessment framework. Currently, there are no internationally recognized science-based ways to assess the humaneness of pesticides and there is no new information to support developing an assessment.
In addition, provincial and territorial governments are responsible for and have measures in place to address both wildlife management and animal welfare.
Based on these considerations, Health Canada did not assess humaneness as part of the re-evaluation on the predacide uses of strychnine and sodium monofluoroacetate.
For more information:
2018 Consultation: Humane Vertebrate Pest Control
2021 Consultation Summary – Humane Vertebrate Pest Control
Framework for risk assessment and risk management of pest control products: PMRA guidance document
Next steps
For strychnine
All cancelled strychnine products will be phased out within six-months from the publication date of this final decision.
During this phase-out period, authorized people may continue using strychnine products in Alberta. It will be prohibited to manufacture, sell or import the products into Canada.
For sodium monofluoroacetate
The risk-reduction measures required as conditions for continued registration must be implemented within 24 months from the publication date of this final decision. This includes product label updates and the product stewardship program.
How to find out more
For more information on RVD2024-04:
Request the full decision document to read the Science Evaluation that is the basis of this final regulatory decision.
Submit questions to Information Services Inquiry – Public Engagement Portal (PEP) (canada.ca).
Please refer to the document title when submitting questions. For example: RVD2024-04: Re-evaluation decision for predacide uses of strychnine and sodium monofluoroacetate and their associated end-use products.
To request additional information on the supporting scientific documents for this final regulatory decision, here is the information you will need to help identify the request:
Active ingredient(s): strychnine, sodium monofluoroacetate
Published document number: RVD2024-04
Submission number(s): 2021-0171, 2021-0172
Related regulatory decision(s): PRVD2022-18
Product labels for strychnine or sodium monofluoroacetate
A list of products containing strychnine or sodium monofluoroacetate registered in Canada is available in the final re-evaluation decision document.
You can also view online all of the products that are currently registered by following these steps:
Access the Label search.
Under the header Filter, select the field “Active Ingredient – English.”
Enter “[active ingredient]” in the Value area.
Click the Search button.
Related information
The technical details of related scientific evaluations and changes to the way strychnine and sodium monofluoroacetate have been used in Canada over the years are in the following list of documents. If you would like to view a full document, please visit the publications page and make a request.
Pesticides and pest management consultations:
Proposed Re-evaluation Decision PRVD2022-18, Predacide Uses of Strychnine and Sodium Monofluoroacetate and their Associated End-use Products – Canada.ca
Decisions and updates:
Request Publication page for PMRA (RVD2014-03) Special Review for Compound 1080
Other related information:
2018 Consultation: Humane Vertebrate Pest Control
2021 Consultation Summary – Humane Vertebrate Pest Control
